
This study has established oleic acid reaction pathways under long-term continuous-flow hydroprocessing, highlighting the roles of metal and acid sites for efficient deoxygenation. At industrially relevant conversions, guaiacol co-feeding, despite accelerating catalyst deactivation, largely preserved the oleic-acid–derived fingerprint (83 wt% of the organic fraction) with mixed-origin products accounting for the remainder. These findings allow tailoring sustainable aviation fuel composition while diversifying non-conventional feedstocks.